/*
 * Simple MTD partitioning layer
 *
 * (C) 2000 Nicolas Pitre <nico@cam.org>
 *
 * This code is GPL
 *
 *      02-21-2002      Thomas Gleixner <gleixner@autronix.de>
 *                      added support for read_oob, write_oob
 */

#include <common.h>
#include <malloc.h>
#include <asm/errno.h>

#include <linux/types.h>
#include <linux/list.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/compat.h>

/* Our partition linked list */
struct list_head mtd_partitions;

/* Our partition node structure */
struct mtd_part {
        struct mtd_info mtd;
        struct mtd_info *master;
        u_int32_t offset;
        int index;
        struct list_head list;
        int registered;
};

/*
 * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
 * the pointer to that structure with this macro.
 */
#define PART(x)  ((struct mtd_part *)(x))


/*
 * MTD methods which simply translate the effective address and pass through
 * to the _real_ device.
 */

static int part_read (struct mtd_info *mtd, loff_t from, size_t len,
                        size_t *retlen, u_char *buf)
{
        struct mtd_part *part = PART(mtd);
        int res;

        if (from >= mtd->size)
                len = 0;
        else if (from + len > mtd->size)
                len = mtd->size - from;
        res = part->master->read (part->master, from + part->offset,
                                   len, retlen, buf);
        if (unlikely(res)) {
                if (res == -EUCLEAN)
                        mtd->ecc_stats.corrected++;
                if (res == -EBADMSG)
                        mtd->ecc_stats.failed++;
        }
        return res;
}

#ifdef MTD_LINUX
static int part_point (struct mtd_info *mtd, loff_t from, size_t len,
                        size_t *retlen, void **virt, resource_size_t *phys)
{
        struct mtd_part *part = PART(mtd);
        if (from >= mtd->size)
                len = 0;
        else if (from + len > mtd->size)
                len = mtd->size - from;
        return part->master->point (part->master, from + part->offset,
                                    len, retlen, virt, phys);
}

static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
        struct mtd_part *part = PART(mtd);

        part->master->unpoint(part->master, from + part->offset, len);
}
#endif

static int part_read_oob(struct mtd_info *mtd, loff_t from,
                         struct mtd_oob_ops *ops)
{
        struct mtd_part *part = PART(mtd);
        int res;

        if (from >= mtd->size)
                return -EINVAL;
        if (ops->datbuf && from + ops->len > mtd->size)
                return -EINVAL;
        res = part->master->read_oob(part->master, from + part->offset, ops);

        if (unlikely(res)) {
                if (res == -EUCLEAN)
                        mtd->ecc_stats.corrected++;
                if (res == -EBADMSG)
                        mtd->ecc_stats.failed++;
        }
        return res;
}

static int part_read_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t len,
                        size_t *retlen, u_char *buf)
{
        struct mtd_part *part = PART(mtd);
        return part->master->read_user_prot_reg (part->master, from,
                                        len, retlen, buf);
}

static int part_get_user_prot_info (struct mtd_info *mtd,
                                    struct otp_info *buf, size_t len)
{
        struct mtd_part *part = PART(mtd);
        return part->master->get_user_prot_info (part->master, buf, len);
}

static int part_read_fact_prot_reg (struct mtd_info *mtd, loff_t from, size_t len,
                        size_t *retlen, u_char *buf)
{
        struct mtd_part *part = PART(mtd);
        return part->master->read_fact_prot_reg (part->master, from,
                                        len, retlen, buf);
}

static int part_get_fact_prot_info (struct mtd_info *mtd,
                                    struct otp_info *buf, size_t len)
{
        struct mtd_part *part = PART(mtd);
        return part->master->get_fact_prot_info (part->master, buf, len);
}

static int part_write (struct mtd_info *mtd, loff_t to, size_t len,
                        size_t *retlen, const u_char *buf)
{
        struct mtd_part *part = PART(mtd);
        if (!(mtd->flags & MTD_WRITEABLE))
                return -EROFS;
        if (to >= mtd->size)
                len = 0;
        else if (to + len > mtd->size)
                len = mtd->size - to;
        return part->master->write (part->master, to + part->offset,
                                    len, retlen, buf);
}

#ifdef MTD_LINUX
static int part_panic_write (struct mtd_info *mtd, loff_t to, size_t len,
                        size_t *retlen, const u_char *buf)
{
        struct mtd_part *part = PART(mtd);
        if (!(mtd->flags & MTD_WRITEABLE))
                return -EROFS;
        if (to >= mtd->size)
                len = 0;
        else if (to + len > mtd->size)
                len = mtd->size - to;
        return part->master->panic_write (part->master, to + part->offset,
                                    len, retlen, buf);
}
#endif

static int part_write_oob(struct mtd_info *mtd, loff_t to,
                         struct mtd_oob_ops *ops)
{
        struct mtd_part *part = PART(mtd);

        if (!(mtd->flags & MTD_WRITEABLE))
                return -EROFS;

        if (to >= mtd->size)
                return -EINVAL;
        if (ops->datbuf && to + ops->len > mtd->size)
                return -EINVAL;
        return part->master->write_oob(part->master, to + part->offset, ops);
}

static int part_write_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t len,
                        size_t *retlen, u_char *buf)
{
        struct mtd_part *part = PART(mtd);
        return part->master->write_user_prot_reg (part->master, from,
                                        len, retlen, buf);
}

static int part_lock_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t len)
{
        struct mtd_part *part = PART(mtd);
        return part->master->lock_user_prot_reg (part->master, from, len);
}

#ifdef MTD_LINUX
static int part_writev (struct mtd_info *mtd,  const struct kvec *vecs,
                         unsigned long count, loff_t to, size_t *retlen)
{
        struct mtd_part *part = PART(mtd);
        if (!(mtd->flags & MTD_WRITEABLE))
                return -EROFS;
        return part->master->writev (part->master, vecs, count,
                                        to + part->offset, retlen);
}
#endif

static int part_erase (struct mtd_info *mtd, struct erase_info *instr)
{
        struct mtd_part *part = PART(mtd);
        int ret;
        if (!(mtd->flags & MTD_WRITEABLE))
                return -EROFS;
        if (instr->addr >= mtd->size)
                return -EINVAL;
        instr->addr += part->offset;
        ret = part->master->erase(part->master, instr);
        if (ret) {
                if (instr->fail_addr != 0xffffffff)
                        instr->fail_addr -= part->offset;
                instr->addr -= part->offset;
        }
        return ret;
}

void mtd_erase_callback(struct erase_info *instr)
{
        if (instr->mtd->erase == part_erase) {
                struct mtd_part *part = PART(instr->mtd);

                if (instr->fail_addr != 0xffffffff)
                        instr->fail_addr -= part->offset;
                instr->addr -= part->offset;
        }
        if (instr->callback)
                instr->callback(instr);
}
#ifdef MTD_LINUX
EXPORT_SYMBOL_GPL(mtd_erase_callback);
#endif

#ifdef MTD_LINUX
static int part_lock (struct mtd_info *mtd, loff_t ofs, size_t len)
{
        struct mtd_part *part = PART(mtd);
        if ((len + ofs) > mtd->size)
                return -EINVAL;
        return part->master->lock(part->master, ofs + part->offset, len);
}

static int part_unlock (struct mtd_info *mtd, loff_t ofs, size_t len)
{
        struct mtd_part *part = PART(mtd);
        if ((len + ofs) > mtd->size)
                return -EINVAL;
        return part->master->unlock(part->master, ofs + part->offset, len);
}
#endif

static void part_sync(struct mtd_info *mtd)
{
        struct mtd_part *part = PART(mtd);
        part->master->sync(part->master);
}

#ifdef MTD_LINUX
static int part_suspend(struct mtd_info *mtd)
{
        struct mtd_part *part = PART(mtd);
        return part->master->suspend(part->master);
}

static void part_resume(struct mtd_info *mtd)
{
        struct mtd_part *part = PART(mtd);
        part->master->resume(part->master);
}
#endif

static int part_block_isbad (struct mtd_info *mtd, loff_t ofs)
{
        struct mtd_part *part = PART(mtd);
        if (ofs >= mtd->size)
                return -EINVAL;
        ofs += part->offset;
        return part->master->block_isbad(part->master, ofs);
}

static int part_block_markbad (struct mtd_info *mtd, loff_t ofs)
{
        struct mtd_part *part = PART(mtd);
        int res;

        if (!(mtd->flags & MTD_WRITEABLE))
                return -EROFS;
        if (ofs >= mtd->size)
                return -EINVAL;
        ofs += part->offset;
        res = part->master->block_markbad(part->master, ofs);
#ifdef MTD_LINUX
        if (!res)
                mtd->ecc_stats.badblocks++;
#endif
        return res;
}

/*
 * This function unregisters and destroy all slave MTD objects which are
 * attached to the given master MTD object.
 */

int del_mtd_partitions(struct mtd_info *master)
{
        struct list_head *node;
        struct mtd_part *slave;

        for (node = mtd_partitions.next;
             node != &mtd_partitions;
             node = node->next) {
                slave = list_entry(node, struct mtd_part, list);
                if (slave->master == master) {
                        struct list_head *prev = node->prev;
                        __list_del(prev, node->next);
                        if(slave->registered)
                                del_mtd_device(&slave->mtd);
                        kfree(slave);
                        node = prev;
                }
        }

        return 0;
}

/*
 * This function, given a master MTD object and a partition table, creates
 * and registers slave MTD objects which are bound to the master according to
 * the partition definitions.
 * (Q: should we register the master MTD object as well?)
 */

int add_mtd_partitions(struct mtd_info *master,
                       const struct mtd_partition *parts,
                       int nbparts)
{
        struct mtd_part *slave;
        u_int32_t cur_offset = 0;
        int i;

        /*
         * Need to init the list here, since LIST_INIT() does not
         * work on platforms where relocation has problems (like MIPS
         * & PPC).
         */
        if (mtd_partitions.next == NULL)
                INIT_LIST_HEAD(&mtd_partitions);

        printk (KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);

        for (i = 0; i < nbparts; i++) {

                /* allocate the partition structure */
                slave = kzalloc (sizeof(*slave), GFP_KERNEL);
                if (!slave) {
                        printk ("memory allocation error while creating partitions for \"%s\"\n",
                                master->name);
                        del_mtd_partitions(master);
                        return -ENOMEM;
                }
                list_add(&slave->list, &mtd_partitions);

                /* set up the MTD object for this partition */
                slave->mtd.type = master->type;
                slave->mtd.flags = master->flags & ~parts[i].mask_flags;
                slave->mtd.size = parts[i].size;
                slave->mtd.writesize = master->writesize;
                slave->mtd.oobsize = master->oobsize;
                slave->mtd.oobavail = master->oobavail;
                slave->mtd.subpage_sft = master->subpage_sft;

                slave->mtd.name = parts[i].name;
                slave->mtd.owner = master->owner;

                slave->mtd.read = part_read;
                slave->mtd.write = part_write;

#ifdef MTD_LINUX
                if (master->panic_write)
                        slave->mtd.panic_write = part_panic_write;

                if(master->point && master->unpoint){
                        slave->mtd.point = part_point;
                        slave->mtd.unpoint = part_unpoint;
                }
#endif

                if (master->read_oob)
                        slave->mtd.read_oob = part_read_oob;
                if (master->write_oob)
                        slave->mtd.write_oob = part_write_oob;
                if(master->read_user_prot_reg)
                        slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
                if(master->read_fact_prot_reg)
                        slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
                if(master->write_user_prot_reg)
                        slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
                if(master->lock_user_prot_reg)
                        slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
                if(master->get_user_prot_info)
                        slave->mtd.get_user_prot_info = part_get_user_prot_info;
                if(master->get_fact_prot_info)
                        slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
                if (master->sync)
                        slave->mtd.sync = part_sync;
#ifdef MTD_LINUX
                if (!i && master->suspend && master->resume) {
                                slave->mtd.suspend = part_suspend;
                                slave->mtd.resume = part_resume;
                }
                if (master->writev)
                        slave->mtd.writev = part_writev;
                if (master->lock)
                        slave->mtd.lock = part_lock;
                if (master->unlock)
                        slave->mtd.unlock = part_unlock;
#endif
                if (master->block_isbad)
                        slave->mtd.block_isbad = part_block_isbad;
                if (master->block_markbad)
                        slave->mtd.block_markbad = part_block_markbad;
                slave->mtd.erase = part_erase;
                slave->master = master;
                slave->offset = parts[i].offset;
                slave->index = i;

                if (slave->offset == MTDPART_OFS_APPEND)
                        slave->offset = cur_offset;
                if (slave->offset == MTDPART_OFS_NXTBLK) {
                        slave->offset = cur_offset;
                        if ((cur_offset % master->erasesize) != 0) {
                                /* Round up to next erasesize */
                                slave->offset = ((cur_offset / master->erasesize) + 1) * master->erasesize;
                                printk(KERN_NOTICE "Moving partition %d: "
                                       "0x%08x -> 0x%08x\n", i,
                                       cur_offset, slave->offset);
                        }
                }
                if (slave->mtd.size == MTDPART_SIZ_FULL)
                        slave->mtd.size = master->size - slave->offset;
                cur_offset = slave->offset + slave->mtd.size;

                printk (KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
                        slave->offset + slave->mtd.size, slave->mtd.name);

                /* let's do some sanity checks */
                if (slave->offset >= master->size) {
                                /* let's register it anyway to preserve ordering */
                        slave->offset = 0;
                        slave->mtd.size = 0;
                        printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
                                parts[i].name);
                }
                if (slave->offset + slave->mtd.size > master->size) {
                        slave->mtd.size = master->size - slave->offset;
                        printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",
                                parts[i].name, master->name, slave->mtd.size);
                }
                if (master->numeraseregions>1) {
                        /* Deal with variable erase size stuff */
                        int i;
                        struct mtd_erase_region_info *regions = master->eraseregions;

                        /* Find the first erase regions which is part of this partition. */
                        for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
                                ;

                        for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
                                if (slave->mtd.erasesize < regions[i].erasesize) {
                                        slave->mtd.erasesize = regions[i].erasesize;
                                }
                        }
                } else {
                        /* Single erase size */
                        slave->mtd.erasesize = master->erasesize;
                }

                if ((slave->mtd.flags & MTD_WRITEABLE) &&
                    (slave->offset % slave->mtd.erasesize)) {
                        /* Doesn't start on a boundary of major erase size */
                        /* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
                        slave->mtd.flags &= ~MTD_WRITEABLE;
                        printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
                                parts[i].name);
                }
                if ((slave->mtd.flags & MTD_WRITEABLE) &&
                    (slave->mtd.size % slave->mtd.erasesize)) {
                        slave->mtd.flags &= ~MTD_WRITEABLE;
                        printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
                                parts[i].name);
                }

                slave->mtd.ecclayout = master->ecclayout;
                if (master->block_isbad) {
                        uint32_t offs = 0;

                        while(offs < slave->mtd.size) {
                                if (master->block_isbad(master,
                                                        offs + slave->offset))
                                        slave->mtd.ecc_stats.badblocks++;
                                offs += slave->mtd.erasesize;
                        }
                }

#ifdef MTD_LINUX
                if (parts[i].mtdp) {
                        /* store the object pointer
                         * (caller may or may not register it */
                        *parts[i].mtdp = &slave->mtd;
                        slave->registered = 0;
                } else {
                        /* register our partition */
                        add_mtd_device(&slave->mtd);
                        slave->registered = 1;
                }
#else
                /* register our partition */
                add_mtd_device(&slave->mtd);
                slave->registered = 1;
#endif
        }

        return 0;
}

#ifdef MTD_LINUX
EXPORT_SYMBOL(add_mtd_partitions);
EXPORT_SYMBOL(del_mtd_partitions);
#endif